iPhone users in Brazil who also subscribe to a magazine called Capricho recently got an extra bonus in one issue. But it wasn't a promo code for a free iTunes track or anything like that. No, it was a special printed cover that turned the rolled up magazine into a passive amplifying speaker for their phone.

The clever stunt was, not surprisingly, an advertisement for Coca-Cola—specifically a special promotion that was running in South America. But if you study the video carefully and are handy with a hobby knife, there's no reason you couldn't also turn a copy of Sports Illustrated or National Geographic into a similar speaker dock that isn't shilling sugar water.